Abstract: Objective: To reseach the expression of Syk in breast cancer tissues and the relation-ship between Syk and the clinical pathology. and other parameters.Methods: The content of Sky mR-NA in the tissues of breast tumor was detected by reverse transcription-polymerase chain reaction (RT-PCR), and Syk, cerbB-2, Cath-D, the expression of VEGF protein in malignant tissues were examinedusing immunohistochemical s-p method.Results: There was a significant difference in the expression ofSYK mRNA and Syk protein between in the malignant and non-cancerous breast tissues (P<0.01); theexpression of Syk protein was related to the distant metastasis and survival rate (P<0.01), but was notrelated to other clinicopathologic factors such as cerbB-2, Cath-D and VEGF protein, and the clinicalstage as well as histological grade or axillary lymph node (P>0.05).Conclusion: The reduced expres-sion of Syk in breast probably plays an important role in the malignant growth of the cells and relates topoor prognosis of breast cancer.